1. Field of the Invention
The present invention relates to a pulse tube refrigerating system, and in particular to a refrigerating system which is used, for example, to cool a super conductive filter of a mobile communication system.
2. Description of the Related Art
One of the conventional pulse tube refrigerating systems is disclosed in, for example, Japanese Laid Open Patent Print No. 9-119731 published, without examination, on May 6, 1997. In the conventional pulse tube refrigerating system, a working gas stored in a buffer is expected to be supplied into a high temperature end of a pulse tube through a pipe or conduit. The pipe is extended from the buffer and is connected to the high temperature side of the pulse tube at right angles. Such a connection means that, when the working gas entered the high temperature end of the pulse tube, the resultant working gas collides with an inner surface of the pulse tube, thereby reducing the temperature. Thus, a direct access or short-circuit approach of the working gas to a lower temperature of the pulse tube is prevented, whereby a cooling ability of the system can be improved theoretically.
However, the foregoing gas is reflected in all directions and the resultant convection of the working gas disturbs the flow of the working gas in the pulse tube, resulting in the generation of eddies of the working gas. This generation brings rapid flow of the working gas toward the low temperature side of the pulse tube, thereby failing to attain the intended cooling ability. Moreover, the pipe is provided therein with an adjusting valve or an orifice to establish a phase difference between displacement and pressure variation of the working gas. Such a structure is cumbersome to assemble.